Server - Reset the DSRM Administrator Password

When you execute AD backup, with any Backup utility, during AD restore procedure you will be prompted about Domain Controller password creation.

So, if you have lost this password, you are unable to restore AD.

Here is relative procedure to reset this password before disaster:

Oritinal Technet Article:

http://support.microsoft.com/kb/322672/en-us 

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This article describes how to reset the Directory Services Restore Mode (DSRM) administrator password for any server in your domain without restarting the server in DSRM. Microsoft Windows 2000 uses the Setpwd utility to reset the DSRM password. In Microsoft Windows Server 2003, that functionality has been integrated into the NTDSUTIL tool. Note that you cannot use the procedure that is described in this article if the target server is running in DSRM. A member of the Domain Administrators group sets the DSRM administrator password during the promotion process for the domain controller. You can use Ntdsutil.exe to reset this password for the server on which you are working, or for another domain controller in the domain.

To Reset the DSRM Administrator Password

1. Click, Start, click Run, type ntdsutil, and then click OK.
2. At the Ntdsutil command prompt, type set dsrm password.
3. At the DSRM command prompt, type one of the following lines:
   • To reset the password on the server on which you are working, type reset password on server null. The null variable assumes that the DSRM password is being reset on the local computer. Type the new password when you are prompted. Note that no characters appear while you type the password.
     
     -or-
   • To reset the password for another server, type reset password on server servername, where servername is the DNS name for the server on which you are resetting the DSRM password. Type the new password when you are prompted. Note that no characters appear while you type the password.
4. At the DSRM command prompt, type q.
5. At the Ntdsutil command prompt, type q to exit.

APPLIES TO

• Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
• Microsoft Windows Server 2003, Standard Edition (32-bit x86)
• Microsoft Windows Small Business Server 2003 Premium Edition
• Microsoft Windows Small Business Server 2003 Standard Edition
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About Other Server and O.S. you can follow this article too:

http://technet.microsoft.com/en-us/library/cc754363.aspx

Applies To: Windows 8, Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2008, Windows Server 2012